bio

Organismal ecology

focuses
on the ways that
species adapt to
their environments
over time through
physiology and
behavior.

Population
ecology

is
concerned with
the factors that
affect population
size, growth,
and density

community
ecology

questions focus
on interactions
among species

Ecosystem
ecology

is
concerned with
questions of
energy flow and
chemical cycling

biotic
factors

The living organisms of

an ecosystem

constitute its

abiotic factors

of

an ecosystem are its

nonliving components

Temperature

has a strong influence on the geographic distribution of species & Dramatic changes in it can lead to localized extinctions

Water

availability has important effects on the abundance

of individuals in populations

what impacts NPP?

light, temperature, and nutrient availability

pH of soil

can impact the distribution and number of

species in areas

The amount of incoming solar radiation varies with

latitude

Proximity to ___ moderates the environment within a region

a major body of water (ocean currents)

Topography

diversifies the environment within a region or locale

Tundra

long, very cold winters

permafrost - frozen soil

Boreal Forests / Taiga (Coniferous Forests)

largest terrestrial biome on Earth

long, cold winters & short, wet summers

coniferous trees dominate (relatively low biodiversity)

thin, acidic, nutrient-poor soils

Temperate Deciduous Forest

wide rage of seasonal temperatures (usually 4 distinct seasons)

deciduous trees dominate (relatively high biodiversity)

relatively nutrient-rich soils

Tropical Forests

temperature - “summer” year-round

precipitation can vary - wet or wet/dry

habitat complexity yields high biodiversity

nutrient poor, acidic soils

Temperate Grasslands

treeless except along rivers and streams (fire maintained)

hot dry summers and cold winters

tallgrass, mixed-grass and short grass prairies

historically deep, nutrient-rich soils

Chaparral

Mediterranean climate

spiny shrubs dominate

fire-dependent

vegetation

fragile soils prone to

mudslides

Deserts

very hot by day, cold by night, and very dry (monsoon season)

succulent cacti and spiny shrubs

plants and animals greatly influence soil nutrients

The _____is the selective pressure of natural selection.

environment

Ecology

is the study of how organisms interact with each other and with the environment

Examples of abiotic factors

temperature, wind, water, light, pH, fire

Abiotic factors

have a profound impact on the geographic distribution of species, ecosystem NPP, biodiversity of an area, and number of individuals in populations of species

Jean Baptiste Lamarck

proposed the first model of evolution with inheritance of acquired characteristic as the mechanism for evolutionary change.

descent with modification

is the evolution of species from ancestral species as changes accumulate over time

Natural selection

is differential reproductive success that results from interactions between heritable variation in a population and the environment.

Evidence of biological evolution comes from

(1) studies of natural selection, (2) selective breeding/artificial selection, (3) biogeography, (4) convergent evolution, (5) the fossil record, and (6) homologies.

Gene transfer, mutations, and natural selection

produce bacterial strains resistant to antibiotics

HIPPCO

Habitat destruction, Invasive species, Population growth (human), Pollution, Climate change, and Overharvesting

Ways to lower the TFR

(1) providing secondary education to all (especially girls), (2) eradicating gender bias from law, economic opportunity, health care, and culture, and (3) providing substantive government-sponsored family planning programs

ecological footprint

is an estimate of the amount of land and water required to sustain one person

Earth's global climate is influenced by

Malankovitch Cycles

Short-term climate changes are caused by

the accumulation of excess greenhouse gases in the atmosphere and an intensification of Earth's greenhouse effect

The greenhouse effect prevents

Earth's nighttime temperatures from dropping below the threshold modern species can tolerate

greenhouse gases

carbon dioxide, methane, nitrous oxide, chlorofluorocarbons, and water vapor

Biomagnification

the tendency of certain chemical pollutants to concentrate in higher trophic levels in food chains

Habitat destruction

is a major threat to Earth's biodiversity, particularly in tropical forests

Overexploitation

the unsustainable human harvest of species. On average, humans decrease prey populations much more than natural predators

Invasive species

those that have been introduced into new geographic areas by people and spread (outcompete native species) on their own without human assistance

Biodiversity

is driven by species adaptations to the environment

Biodiversity encompasses

(1) genetic diversity of a species, (2) variety of species in an area, and (3) variety of ecosystems on an landscape

biophilia

term coined by EO Wilson to describe the connectedness that humans feel to nature. We are part of something larger than ourselves

Conservation biology

is a branch of ecology that works to preserve biodiversity

Restoration ecology

restores degraded habitats

Conservation biologists argue

for the preservation of biodiversity hotspots

Conservation biologists advocate

for the creation and maintenance of nature preserves

Conservation biologists and restoration ecologists use

methods to correct habitat fragmentation, as well as bioremediation to maintain the diversity of habitats that species evolved in and are adapted to

IUCN

declare species as threatened, vulnerable, or endangered

Genetic variation is measured

as the allele and genotype frequencies in a population's gene pool

populations

natural selection acts upon

Genetic variation

the substrate of natural selection

Sources of genetic variation in a population's gene pool

mutation and sexual recombination [meiosis (crossing over and independent assortment of chromosomes) and random fusion of gametes at fertilization]

criteria of Hardy-Weinberg Equilibrium

no mutations, isolation from other populations, random mating, large population size, and no natural selection

agents of evolutionary change (mechanisms)

mutation, gene flow, nonrandom mating, genetic drift, and/or selection

Balancing selection

maintains balanced polymorphisms in the gene pool via heterozygous advantage and negative frequency-dependent selection

Sexual selection

some individuals along a phenotypic distribution are more successful at attracting mates and, therefore have higher fitness

Genetic drift leads to

a loss of genetic variation in a population's gene pool

Genetic drift is brought on by

the bottleneck effect or founder effect

Gene flow occurs when

individuals migrate between populations with allele frequencies

Speciation can occur when

some event separates a population by time, space, or genetics. Population then diverge along their own evolutionary path.